U.S. patent application number 10/188403 was filed with the patent office on 2002-11-07 for introducer sheath with retainer.
This patent application is currently assigned to Rex Medical. Invention is credited to McGuckin, James F. JR., Tashjian, Paul.
Application Number | 20020165489 10/188403 |
Document ID | / |
Family ID | 26941695 |
Filed Date | 2002-11-07 |
United States Patent
Application |
20020165489 |
Kind Code |
A1 |
McGuckin, James F. JR. ; et
al. |
November 7, 2002 |
Introducer sheath with retainer
Abstract
A surgical introducer sheath comprising a first member having a
first longitudinally extending lumen dimensioned to receive a
surgical instrument therethrough, a second member having a second
longitudinally extending lumen dimensioned to receive the first
member, and a retainer adjacent a distal portion of the second
member movable from a first retracted position to a second extended
position to limit proximal movement of the introducer sheath.
Rotational movement of the second member in a first direction moves
the retainer to the extended position and rotational movement of
the second member in a second direction moves the retainer to a
retracted position.
Inventors: |
McGuckin, James F. JR.;
(Radnor, PA) ; Tashjian, Paul; (King of Prussia,
PA) |
Correspondence
Address: |
Neil D. Gershon
Rex Medical
Suite 2
2023 Summer St.
Stamford
CT
06905
US
|
Assignee: |
Rex Medical
|
Family ID: |
26941695 |
Appl. No.: |
10/188403 |
Filed: |
July 2, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10188403 |
Jul 2, 2002 |
|
|
|
09996437 |
Nov 28, 2001 |
|
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|
60251567 |
Dec 6, 2000 |
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Current U.S.
Class: |
604/109 ;
604/117; 606/198 |
Current CPC
Class: |
A61M 25/0662 20130101;
A61M 2039/062 20130101; A61M 2039/0633 20130101; A61M 2039/0653
20130101; A61M 39/0606 20130101; A61M 2039/0686 20130101; A61M
29/00 20130101; A61M 2025/0681 20130101; A61M 25/04 20130101; A61M
39/045 20130101; A61M 2039/064 20130101 |
Class at
Publication: |
604/109 ;
606/198; 604/117 |
International
Class: |
A61M 029/00 |
Claims
What is claimed is:
1. A surgical vascular introducer sheath comprising: a first member
having a first longitudinally extending lumen configured and
dimensioned to receive a surgical instrument therethrough; a second
member having a second longitudinally extending lumen configured
and dimensioned to receive the first member; and a retainer
adjacent a distal portion of the second member, the retainer
movable from a first retracted position to a second extended
position to limit proximal movement of the introducer sheath, the
retainer movable in response to movement of the second member.
2. The introducer sheath of claim 1, wherein rotational movement of
the second member in a first direction moves the retainer to the
extended position and rotational movement of the second member in a
second direction moves the retainer to the retracted position.
3. The introducer sheath of claim 2, wherein the second member is
substantially fixed longitudinally during rotation.
4. The introducer sheath of claim 2, wherein the retainer comprises
a flap having a substantially curved configuration in the extended
position.
5. The introducer sheath of claim 4, wherein the flap includes an
opening to allow blood flow therethrough when in the extended
position.
6. The introducer sheath of claim 2, wherein a first portion of the
retainer extends from the second member and a second portion of the
retainer is attached to the first member.
7. The introducer sheath of claim 1, further comprising a second
retainer movable between retracted and extended positions.
8. The introducer sheath of claim 1, wherein the first and second
members each have a plurality of side holes for blood flow for
dialysis.
9. The introducer sheath of claim 8, wherein rotational movement of
the second member in a first direction moves the retainer to the
extended position and rotational movement of the second member in a
second direction moves the retainer to a retracted position,
wherein the side holes of the first and second members are out of
alignment when the retainer is in the retracted position and the
side holes are moved into alignment when the second member is
rotated to move the retainer into the extended position.
10. The introducer sheath of claim 2, further comprising a locking
mechanism for maintaining the retainer in the extended
position.
11. The introducer sheath of claim 10, wherein the locking
mechanism comprises a locking pin slidable within a locking groove,
the groove having a narrowed section to retain the pin.
12. The introducer sheath of claim 10, wherein the locking
mechanism comprises a post movable within a locking groove, the
locking groove having a radial region and first and second axial
regions.
13. The introducer sheath of claim 11, further comprising a
housing, wherein a proximal portion of the first and second members
are positioned within the housing, the locking groove being
positioned on the housing and the locking pin extending from the
second member.
14. The introducer sheath of claim 1, wherein the retainer
comprises a flap formed integrally with the second member.
15. The introducer sheath of claim 1, further comprising a
radiopaque insert at a distal end of the sheath.
16. The introducer sheath of claim 15, wherein the radiopaque
insert is blended with a distal portion of the second member during
formation of a tip of the sheath.
17. The introducer sheath of claim 16, wherein the radiopaque
insert extends to the distalmost tip of the second member, and
after formation has an inner diameter substantially equal to an
inner diameter of the first member.
18. A surgical sheath for providing a passageway for
instrumentation into a vessel comprising: a tubular member having a
lumen extending longitudinally therein configured and dimensioned
for receiving surgical instruments therethrough, the tubular member
having a distalmost tip; and means spaced proximally from the
distalmost tip for limiting proximal movement of the sheath with
respect to the vessel, the limiting means being movable from a
first position to a second position extending laterally with
respect to the tubular member and enabling blood flow therethrough
in the second position.
19. The surgical sheath of claim 18, wherein the tubular member
includes an inner and outer tubular member and the limiting means
comprises a flap movable to the second position in response to
rotational movement of the outer tube.
20. The surgical sheath of claim 18, wherein the first and second
members each have a plurality of side holes for blood flow for
dialysis, wherein the side holes of the first and second members
are out of alignment when the retainer is in the retracted position
and the side holes are moved into alignment when the second member
is rotated to move the retainer into the extended position.
21. The surgical sheath of claim 18, wherein the tubular member
includes an inner and outer tube, and the limiting means comprises
first and second flaps movable to the extended position in response
to rotational movement of the outer tube.
22. The surgical sheath of claim 18, further comprising a
radiopaque insert at a distal end of the sheath, the radiopaque
insert blended with a portion of the tubular member at the
distalmost tip during formation thereof.
23. A surgical sheath for providing a passageway for
instrumentation into a vessel comprising: an outer tubular member
having a first hole in a side wall; an inner tubular member
disposed within the outer tubular member and having a passageway
for receiving surgical instruments therethrough and having a second
hole in a side wall; a retainer positioned at a distal portion of
the outer tubular member and extendable radially with respect to
the outer tubular member, the retainer being movable from a
non-blocking position substantially flush with the outer tubular
member to a blocking position extending radially outwardly from the
outer tubular member.
24. The surgical sheath of claim 23, wherein the retainer is
movable to the blocking position in response to rotation of the
outer tubular member
25. The surgical sheath of claim 24, further comprising a locking
element for locking the retainer in the blocking position.
26. The surgical sheath of claim 25, wherein the first and second
holes of the inner and outer tubular members are rotatable into
alignment by rotation of the outer tubular member to align the
holes to enable blood flow for dialysis.
27. The surgical sheath of claim 26, further comprising a locking
mechanism for maintaining the retainer in the blocking position,
the locking mechanism including a locking pin slidable within a
locking groove having a narrowed section to retain the pin, the
locking pin extending from the second member and the locking groove
being positioned on a housing which receives the inner and outer
tubular members.
28. The surgical sheath of claim 26, further comprising a locking
mechanism for maintaining the retainer in the blocking position,
the locking mechanism including a locking post slidable within a
locking groove, the locking post extending from the second member
and the locking groove being positioned on a cap mounted to the
inner tubular member.
29. The introducer sheath of claim 27, further comprising a seal
member positioned on the inner tube to provide a fluid seal between
the inner and outer tubular members.
30. A method for retaining a surgical introducer sheath comprising
the steps of: inserting an introducer having inner and outer
tubular members and a retainer into body tissue; rotating the outer
tubular member of the introducer sheath to move the retainer from a
retracted position to an extended position so the retainer extends
radially outwardly with respect to the introducer sheath,
introducing a surgical instrument into the introducer sheath;
performing a surgical step with the surgical instrument;
withdrawing the surgical instrument, the retainer limiting proximal
movement of the introducer sheath during withdrawal of the surgical
instrument; and rotating the outer tubular member of the introducer
sheath to return the retainer to its retracted position.
31. The method of claim 30, wherein the step of rotating the outer
tubular member to move the retainer from the retracted position to
the extended position aligns holes in the introducer sheath to
allow blood flow for dialysis.
Description
BACKGROUND
[0001] This application claims priority from U.S. application Ser.
No. 09/996,437, filed Nov. 28, 2001 which claims priority from
provisional application serial No. 60/251,567, filed Dec. 6, 2000.
The entire contents of both applications are incorporated herein by
reference.
TECHNICAL FIELD
[0002] This application relates to an introducer sheath and more
particularly to a vascular introducer sheath having a retainer to
prevent dislodgement during use.
BACKGROUND OF RELATED ART
[0003] An introducer sheath is commonly used in vascular surgery as
an access port for surgical instruments. The introducer sheath has
a central passageway to accommodate such instrumentation and is
inserted through a skin incision and into the vessel wall, such as
the renal or femoral artery or vein, so the instruments can access
the interior of the vessel. The introducer sheath can also be
inserted into dialysis grafts to provide access to the graft. The
introducer sheaths have peripheral, cardiac, and neurovascular
applications.
[0004] Once the surgical introducer sheath is placed, various
instruments are inserted and withdrawn through the passageway into
the vessel interior, depending on the surgical procedure. Examples
of such instrumentation include dilators, angioplasty balloon
catheters, stent deployment catheters, angiographic instruments,
thrombectomy devices and embolization instruments. These
instruments typically having an outer diameter close to the
internal diameter of the introducer sheath which means they will
usually abut the inside wall of the sheath. This relatively tight
fit oftentimes results in excessive frictional engagement with the
inside wall of the sheath, causing dislodgement of the sheath
during instrument withdrawal through the passageway in the sheath.
Additionally, surgical instrumentation which include an inflatable
balloon, when initially inserted through the sheath have a smaller
diameter because the balloon is tightly wrapped around the
catheter. However, after the balloon is inflated inside the vessel
and then deflated for withdrawal, it is not as tightly wrapped as
initial insertion. Thus, when the balloon catheter is withdrawn
through the introducer sheath, there is a greater frictional
contact with the inside wall of the sheath and therefore a greater
likelihood of dislodgement.
[0005] Dislodgement of the sheath creates numerous problems. If the
position of the sheath is altered by removal of an instrument, when
the next instrument is inserted, it will not properly be positioned
at the surgical site. Thus the surgeon must undertake the time
consuming task of repositioning the sheath and instrument within
the vessel. The problems with dislodgement become more acute if
withdrawal of the instrument actually pulls the introducer sheath
out of the vessel wall incision altogether. This can occur if there
is sufficient frictional contact with the instrument and introducer
sheath, and a sufficient proximal force is applied by the surgeon.
Such undesirable removal of the introducer sheath can cause loss of
blood, air aspiration which can result in air embolisms possibly
causing stroke, and an increased risk of infection and morbidity.
Additionally, since the surgeon needs to reintroduce the introducer
sheath into the vessel, the surgeon may be unable to locate the
exact prior incision site, thereby having to enlarge the incision
site or create a second incision, thereby causing additional blood
loss and increasing the difficulty of closing the vessel
incision(s) at the end of the procedure. Vessel fatigue can also
result because re-introduction of the sheath requires insertion of
a needle and dilator through the vessel wall.
[0006] Another disadvantage of complete dislodgement of the sheath
is the additional time required to re-introduce the sheath. This
time loss can be especially significant if re-introduction is
required at a critical time of the procedure. That is, if the
sheath is fully withdrawn from the vessel, access to the vessel
will be temporarily denied, thereby interrupting the surgical
procedure which can mean appropriate instrumentation, perhaps even
life-saving instrumentation, cannot be inserted to the surgical
site.
[0007] Due to the concern of dislodgement, surgeons sometimes
over-insert the introducer sheath so the tip is spaced further from
the incision. This way, if the sheath is inadvertently pulled
proximally, it will have some room to move before it is pulled out
fully from the incision. However, over-insertion of the introducer
sheath can adversely affect surgical access as the surgical site
can be blocked by the sheath, especially if the site is adjacent
the incision.
[0008] Therefore, it would be advantageous to provide a mechanism
to retain the introducer sheath within the vessel. However, such
mechanism needs to be configured so as not to damage the vessel
wall. Consequently, a retaining mechanism must effectively strike a
balance between sufficient strength to retain the introducer sheath
while providing atraumatic contact with the vessel wall.
[0009] The need therefore exists for an atraumatic introducer
sheath which has greater retention capabilities, to thereby
minimize the chances of dislodgement. By minimizing the likelihood
of dislodgement, the foregoing risks to the patient would
advantageously be eliminated.
SUMMARY
[0010] The present invention overcomes the disadvantages and
deficiencies of the prior introducer sheaths by advantageously
providing an introducer sheath having a retainer that is
selectively extendable with respect to the sheath, thereby
functioning to retain the sheath within the vessel. Extending the
retainer radially from the sheath creates an enlarged diameter
region greater than the diameter of the incision into the vessel to
prevent withdrawal of the sheath through the incision, and in
smaller vessels, enabling the retainer to frictionally engage the
vessel wall to restrict sliding movement of the sheath.
[0011] More specifically, the present invention provides a surgical
vascular introducer sheath comprising a first member having a first
longitudinally extending lumen configured and dimensioned to
receive a surgical instrument therethrough, a second member having
a second longitudinally extending lumen configured and dimensioned
to receive the first member, and a retainer adjacent a distal
portion of the second member movable from a first retracted
position to a second extended position, in response to movement of
the second member, to limit proximal movement of the introducer
sheath. Preferably, rotational movement of the second member in a
first direction moves the retainer to the extended position and
rotational movement in a second direction moves the retainer to the
retracted position. The second member is preferably substantially
fixed longitudinally during rotation.
[0012] Preferably, the retainer comprises a flap having a curved
configuration in the extended position and an opening to allow
blood flow therethrough. Preferably a first portion of the flap
extends from the second member and a second portion of the flap is
attached to the first member.
[0013] The first and second members may each have a plurality of
side holes for blood flow for dialysis wherein the side holes are
out of alignment when the retainer is in the retracted position and
the side holes are moved into alignment when the second member is
rotated to move the retainer into the extended position.
[0014] The introducer sheath may further comprise a locking
mechanism for maintaining the retainer in the extended position.
The locking mechanism may comprise a locking pin slidable within a
locking groove having a narrowed section to retain the pin.
Preferably, a proximal portion of the first and second members are
positioned within a housing with the locking groove positioned on
the housing and the locking pin extending from the second member.
The housing may further have an internal keyway slot to receive a
key extending from the first member to prevent rotation of the
first member. The locking mechanism may alternately comprise a post
slidable within a locking groove having a radial region and first
and second axial regions.
[0015] A radiopaque insert can be provided at a distal end of the
sheath, preferably blended with a distal portion of the second
member during formation of a tip of the sheath. Preferably, the
radiopaque insert extends to the distalmost tip of the second
member, and after formation has an inner diameter substantially
equal to an inner diameter of the first member.
[0016] The present invention also provides a surgical sheath for
providing a passageway for instrumentation into a vessel comprising
a tubular member having a lumen extending longitudinally therein
dimensioned and configured for receiving surgical instruments
therethrough and means spaced proximally from the distalmost tip of
the tubular member for limiting proximal movement of the sheath
with respect to the vessel. The limiting means is movable from a
first position to a second position extending laterally with
respect to the tubular member and enabling blood flow therethrough
in the second position.
[0017] The tubular member preferably includes inner and outer
tubular members and the limiting means preferably comprises a flap
movable to the second position in response to rotational movement
of the outer tube. In an alternate embodiment, the limiting means
comprises first and second flaps movable to the extended position
in response to rotational movement of the outer tubular member.
[0018] The present invention also provides a surgical sheath for
providing a passageway for instrumentation into a vessel comprising
an outer tubular member having a first side hole in a sidewall and
an inner tubular member disposed within the outer tubular member
and having a passageway for receiving surgical instruments
therethrough and having a second hole in a sidewall. A retainer at
a distal portion of the outer tubular member is movable from a
non-blocking position substantially flush with the outer tubular
member to a blocking position extending radially outwardly from the
outer tubular member. The first and second side holes are moved
into alignment when the retainer is moved to its blocking
position.
[0019] A method for retaining a surgical introducer sheath is also
provided comprising:
[0020] inserting an introducer sheath having inner and outer
tubular members and a retainer into body tissue;
[0021] rotating the outer tubular member of the introducer sheath
to move the retainer from a retracted position to an extended
position so the retainer extends radially outwardly,
[0022] introducing a surgical instrument into the introducer
sheath;
[0023] performing a surgical step with the surgical instrument;
[0024] withdrawing the surgical instrument, the retainer limiting
proximal movement of the introducer sheath during withdrawal of the
surgical instrument; and
[0025] rotating the outer tubular member of the introducer sheath
to return the retainer to its retracted position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Preferred embodiment(s) of the present disclosure are
described herein with reference to the drawings wherein:
[0027] FIG. 1 is a perspective view of a first embodiment of the
introducer sheath of the present invention with the retainer in the
retracted position;
[0028] FIG. 2 is a perspective view of the introducer sheath of
FIG. 1 with the retainer in the extended position;
[0029] FIG. 3 is a longitudinal cross-sectional view of the
introducer sheath of FIG. 2 with the retainer in the extended
position;
[0030] FIG. 4 is a transverse cross-sectional view taken along
lines 4-4 of FIG. 3;
[0031] FIG. 5 is a transverse cross-sectional view similar to FIG.
4 except showing the retainer in the retracted position;
[0032] FIG. 6 is a perspective view of the distal portion of a
second embodiment of the introducer sheath of the present invention
having side holes for dialysis and showing the retainer in the
retracted position;
[0033] FIG. 7 is a perspective view of the distal portion of the
introducer sheath of FIG. 6 showing the retainer in the extended
position;
[0034] FIG. 8 is an exploded view of the introducer sheath of FIG.
6;
[0035] FIG. 8A is a transverse cross-sectional view showing the
orientation of the side port and keyway of the housing;
[0036] FIG. 8B is a transverse cross-sectional view showing the
dialysis holes of the inner and outer tubular members out of
alignment prior to deployment of the retainer;
[0037] FIG. 9 is a perspective view of the introducer sheath of
FIG. 6 showing the components in phantom inside the housing;
[0038] FIG. 10 is a perspective view of the introducer sheath of
FIG. 6 showing the tubing extending from the side port for either
blood withdrawal or blood return;
[0039] FIG. 10A is an enlarged view of the locking pin and groove
of FIG. 10;
[0040] FIG. 11 is a perspective view of the distal portion of an
alternate embodiment of the introducer sheath having an angled tip
to facilitate insertion;
[0041] FIG. 12 is a side view of the introducer sheath of FIG.
11;
[0042] FIG. 13 illustrates the introducer sheath of FIG. 6 inside a
vessel with the retainer in the extended position to prevent
withdrawal of the introducer sheath through the incision;
[0043] FIG. 14 illustrates the distal portion of the introducer
sheath of FIG. 6 inserted into a small vessel wherein the retainer,
in its extended position, frictionally engages the vessel wall to
limit proximal movement of the introducer sheath;
[0044] FIG. 15 illustrates a catheter being withdrawn from the
introducer sheath of FIG. 6, the retainer engaging the vessel wall
to limit proximal movement;
[0045] FIG. 16 is a side perspective view of a third embodiment of
the introducer sheath of the present invention;
[0046] FIG. 17 is an exploded view of the introducer sheath of FIG.
16;
[0047] FIG. 18A is a cross-sectional view taken along lines 18A-18A
of FIG. 16;
[0048] FIG. 18B is a cross-sectional view of the valve of FIG.
17;
[0049] FIG. 18C is a cross-sectional view similar to FIG. 18A
illustrating an alternate embodiment of the radiopaque marker of
the introducer sheath of the present invention;
[0050] FIG. 18D illustrates the outer tube of the introducer sheath
and radiopaque insert prior to formation of the tip of FIG.
18C;
[0051] FIG. 19 is an enlarged perspective view of a portion of the
introducer sheath of FIG. 16 showing the ball lock engaged in the
slot; and
[0052] FIG. 20 is a perspective view of a fourth alternate
embodiment of the introducer sheath of the present invention having
two retainers;
[0053] FIG. 21 is a perspective view of a distal portion of a fifth
alternate embodiment of the introducer sheath of the present
invention having two overlapping flaps; and
[0054] FIG. 22 is a front view of the introducer sheath of FIG. 21
showing the overlapping flaps in the extended position.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0055] Introducer sheaths are commonly used in vascular surgery to
provide a passageway for instrumentation. The introducer sheath is
inserted into a vessel or a graft (e.g. a dialysis graft) and a
variety of instruments for performing the specific surgical
procedure are introduced therethrough to access the surgical site.
Since the instruments are repeatedly inserted and withdrawn during
the surgical procedure, and have a diameter closely matching the
internal diameter of the sheath, the introducer sheath has the
tendency to be dislodged, and perhaps even withdrawn from the
vessel incision as discussed above. Additionally, certain
instruments, such as balloon catheters, may have a larger diameter
during withdrawal then insertion, thereby increasing the chances of
dislodgment. The introducer sheaths of the present invention
advantageously have a retainer for limiting proximal movement and
preventing full dislodgement of the introducer sheath during
surgery. That is, the retainer is extendable from the sheath to
create an enlarged diameter or circumferential portion exceeding
the size of the vessel incision and in smaller vessels,
frictionally engaging the vessel wall.
[0056] Referring now in detail to the drawings where like reference
numerals identify similar or like components throughout the several
views, FIGS. 1-5 illustrate a first embodiment of the introducer
sheath of the present invention, designated generally by reference
numeral 10.
[0057] The introducer sheath 10 has a proximal portion 12, a distal
portion 14, an outer tubular member 20 and an inner tubular member
30 disposed concentrically within the outer tubular member 20. A
retainer 40, in the form of a curved or U-shaped flap, extends from
outer tube 20 and is positioned proximally of the distalmost tip.
Retainer 40 is movable from a retracted position where it is
substantially flush with the outer surface 24 of outer tube 20 as
shown in FIG. 1, to an extended (blocking) position where it
extends radially outwardly from the outer tube 20 as shown in FIG.
2. This radial movement increases the overall circumference or
diameter of the outer tube 20, thereby causing the sheath 10 to
engage the vessel wall or wall surrounding the incision in the
manner described below.
[0058] Outer tube 20, preferably circular in cross section as
shown, (although oval or other shapes can be utilized) has a distal
portion 21, a proximal portion 23 and a central longitudinal lumen
22 dimensioned and configured to receive inner tube 30. A cutout in
the outer tube 20 forms flap 40, integrally extending therefrom at
edge 42 and which is attached at edge 43 to outer surface 34 of
inner tube 30. Distal nose 28 of tube 20 is slightly tapered to
facilitate insertion through the incision and vessel.
[0059] Inner tube 30 is also preferably circular in cross section
(although oval or other shapes can be utilized) and has a distal
portion 31 and a proximal portion 33. Central lumen 32 extends
longitudinally along the entire length of the inner tube 30 and is
configured and dimensioned to receive surgical instruments
therethrough, as described below.
[0060] Retainer or flap 40 is deployed by rotation of outer tube
20. The surgeon grasps the knurled surface 29 of proximal portion
23 and rotates the outer tube 20 in the direction of the arrow.
Such rotation causes flap 40 to move to the extended (deployed)
position since flap 40 is attached to inner tube 30 (at edge 43)
which remains stationary. Flap 40 is preferably curved and U-shaped
as shown to form an opening 48 to allow blood flow therethrough and
extend longitudinally alongside outer tube 60 ("L"). The smooth
shaped surface provides atraumatic contact with the vessel
wall.
[0061] FIGS. 6-10 illustrate an alternate embodiment of the
introducer sheath of the present invention. Introducer sheath,
designated generally by reference numeral 50 is similar to
introducer sheath 10 of FIG. I in that it has an outer tube 60, an
inner tube 70 and a flap 80 extending from outer tube 60 and
attached at edge 82 to inner tube 70. Inner tube 70 has a
longitudinal lumen 72 for passage of surgical instruments and outer
tube 60 has a longitudinal lumen 62 to receive inner tube 70. As in
the first embodiment, flap 80, in its retracted position is
substantially flush with outer tube 60 and in its extended
(blocking) position is curved and in a U-shaped configuration to
form opening 83 for blood passage. Flap 80 is preferably integrally
formed with outer tube 60, positioned proximally of the distalmost
tip of the outer tube, and as shown extends longitudinally
alongside a portion of the outer tube 60 as represented by letter
"L".
[0062] Introducer sheath 50 further includes a retainer locking
element to maintain the retainer or flap 80 in the extended
position. Turning now to FIG. 8, outer tube 60 has a locking pin 85
extending from enlarged head 86 which is received within transverse
locking groove 90 of housing 92. As shown in FIGS. 10 and 10A,
locking groove 90 is slightly arcuate and has two lobes 94, 96 at
opposite ends and adjacent narrowed regions 93, 95. When the
retainer is in the retracted position of FIG. 6, locking pin 85 is
seated within lobe 96 and is prevented from movement within the
groove 90 by narrowed region 95. To move the retainer to the
extended position to limit movement of the introducer sheath 50,
locking pin 85 is grasped by the user and moved within groove 90.
By supplying sufficient force, locking pin 85 is forced through
narrowed region 95, slightly stretching the flexible material
around the groove. Movement of locking pin 85 rotates the outer
tube 60, while the inner tube 70 remains stationary, thereby moving
retainer 80 to its extended position. This pin and groove
arrangement also keeps outer tube 60 fixed longitudinally during
rotation.
[0063] To lock the retainer 80 in its extended position, locking
pin 85 is forced through narrowed region 93 into lobe 94. After
being slightly stretched by passage of locking pin 85, narrowed
region 93 returns to its original configuration to block exit of
locking pin 85. Thus, locking pin 85 is prevented from sliding
within locking groove 90, thereby blocking outer tube 60 from
rotation and maintaining retainer 80 in the blocking (extended)
position.
[0064] When it is desired to move retainer 60 back to its retracted
position, locking pin 85 is forced through narrowed regions 93 and
95, by movement in the reverse direction, and returned to lobe 96.
During movement of the outer tube 60 in either direction, inner
tube 70 remains stationary due to the engagement of key 75 of
enlarged head 77 with keyway slot 91 of housing 92, shown in
phantom in FIG. 8. Outer tube 60 is prevented from sliding
longitudinally by groove 90. As an alternative to the keyway, an
adhesive or any energy welding system, e.g. radiofrequency,
ultrasonic, etc., can be utilized to keep the inner tube 70
stationary.
[0065] Visual indicators could optionally be provided at the lobes
to indicate to the user the position of the retainer. For example,
an "R" for retracted can be provided adjacent lobe 96 on the
housing 92 and an "E" for extended can be provided adjacent lobe
94.
[0066] With continued reference to FIG. 8, housing 92 has assembly
slot 99 communicating with groove 90 for ease of assembly. That is,
for assembly, locking pin 95 is slid through slot 99 into groove 90
and locking cap 100 is placed over distal portion 98 of housing 92
effectively closing slot 99 to lock pin 85 within groove 90. A
valve 102 is positioned within housing 92 to prevent outflow of
blood through proximal opening 107 of housing 92. If sheath 50 is
used for dialysis as explained below, the valve is preferably a
silicone valve to accommodate additional pressure from the vacuum
for blood withdrawal. A donut like element 104, preferably composed
of foam and having central opening 105, is positioned between valve
102 and proximal wall 97 of housing 92. Donut 104 is preferably
laced with a lubricant such as silicone to promote lubricity during
insertion of surgical instruments and to prevent valve damage due
to friction.
[0067] Optionally, the introducer sheath can include a plurality of
holes for either blood withdrawal or blood return so the introducer
sheath can remain in the body for dialysis. As shown in FIG. 8,
outer tube has side openings or holes 61 formed through its outer
wall 64 and inner tube 70 has side openings or holes 71 formed
through outer wall 74. These holes 61, 71, when aligned, allow for
passage of blood through lumen 72, out through side aperture 79 in
enlarged head portion 77, and exiting through side port 101 in
housing 92. Conventional tubing 1 10, as shown in FIG. 10, is
connected to side port 101. Tubing 110 includes conventional tube
clamp 112 and luer fitting 114 which do not form part of this
invention and are therefore not further described. If used for
dialysis, two introducer sheaths 50 would be provided: one sheath
50 for withdrawal of blood from the vessel for passage to the
dialysis machine and a second sheath 50 for return of blood from
the dialysis machine to the vessel. Alternatively, if used for
dialysis, introducer sheath 50 could be used for blood withdrawal
or delivery, and another instrument, such as dialysis needle could
be used for opposite blood flow. Also, although three holes are
shown, it should be appreciated that various spacings and fewer or
greater number of holes could be provided for dialysis or for other
procedures.
[0068] It should be appreciated that it is also contemplated that
the sheath need not be provided with any side holes if dialysis or
blood flow for other surgical applications is not intended.
[0069] FIG. 8B illustrates the interaction of the side holes 61 and
71 of the outer and inner tubes 60, 70 respectively. When the
retainer 80 is in the retracted position, holes 61 and 71 are out
of alignment as shown, thereby preventing blood flow through
central lumen 72. However, when outer tube 60 is rotated to extend
retainer 80 to the blocking (extended) position, side holes 61 are
rotated into alignment with side holes 71. Thus when outer tube 60
is locked in the rotated position with locking pin 85 retained in
lobe 94, holes 61 and 71 are in alignment and blood can pass
through these holes into central lumen 72.
[0070] Proximal opening 107 in housing 92 allows for passage of a
guidewire and surgical instruments, the guidewire and surgical
instruments passing through opening 102 in donut 104, and through
valve 102 and opening 106 in cap 100 into central lumen 72.
[0071] FIGS. 11 and 12 illustrate an alternate embodiment of the
introducer sheath having an angled or beveled end to facilitate
insertion. Introducer sheath 120, as shown, has a tip 112 at an
angle greater than 90 degrees so that edge 124 will penetrate
tissue before edge 126, thereby reducing the penetration force.
Such angled tip can be provided on any of the foregoing introducer
sheaths.
[0072] FIGS. 16-19 illustrate a third embodiment of the locking
sheath of the present invention, designated generally by reference
numeral 150. Locking sheath 150 is similar to the foregoing locking
sheaths in that it has a retainer 160 in the form of a U-shaped
flap that is movable between a retracted substantially flush
position to a radially extended position with respect to the outer
tube 162. Locking sheath 150 differs in the locking structure for
the retainer 160 and some of the assembly components.
[0073] More specifically, and with reference to FIG. 17, inner tube
170 extends integrally from housing 172. Side port 179 for mounting
conventional tubing as described above (not shown) is shown angled
at about 45 degrees to reduce mechanical hemolysis. Inner tube 170
is preferably composed of a dark material, achieved for example by
adding carbon black or other particles or by inks or pigments, to
absorb laser wavelengths to create heat to laser weld the retainer
160 to the inner tube 170 (see FIG. 18). Other methods of
attachment are also contemplated.
[0074] Seated inside housing 172 is slit valve 174 and end cap 176.
Slit valve 174 is press fit within a tapered inner surface of
housing 172 and end cap 176 is fitted with recess 175 of housing
172. The end cap 176 preferably has a chamfer to direct instruments
inserted therethrough towards the center. Gasket 178 is
frictionally seated over inner tube 170 to provide a seal between
the inner tube 170 and outer tube 162.
[0075] FIG. 18B shows a preferred embodiment of the slit valve
which can be utilized in the embodiments of FIGS. 8 and 17. For
clarity, the valve is designated generally by reference numeral
300, it being understood that it can correspond to valve 102 or
174.
[0076] Valve 300 has a transverse slit 302 extending through a
central portion of the valve from a top surface 304 to a bottom
surface 306. As shown, the slit 302 is formed so the walls 302a,
302b extend slightly outwardly towards the bottom surface 306 as
shown. A small hole on top surface 304 provides a lead in to the
slit 302. The top surface 304 of the valve 300 is slightly conical
to direct instruments toward the center of the valve. Preferably,
this slight conical surface is at an angle of about 80 degrees,
such that the height h1 of the valve 300 at the outer edge is
preferably about 0.120 inches and the height h2 at the center
adjacent the hole is preferably about 0.098 inches.
[0077] Outer tube 162 has a lumen dimensioned to receive the inner
tube 170. Retainer (flap) 160, extending from outer tube 162 is
welded to inner tube 170. Post 182, terminating in ball 184,
extends from enlarged cylindrical base 186 and functions to lock
the retainer 160 in the retracted position and in the extended
position. More specifically, and with reference to FIGS. 17 and
FIG. 19, a slot 192 is formed in front cap 190. Front cap 190 is
mounted to housing 172 via a U-shaped groove 191 and corresponding
tongue arrangement on housing 172. Slot 192 extends radially along
the surface of cap 190 and has two axially extending regions 194,
196 at its ends. When post 182 is in region 194, the retainer 160
is in its retracted position. To rotate the outer tube 162 to move
the retainer 160 to the extended position, the user pulls post 182
rearwardly (in the direction of the arrow) along first axis region
194, into radial region 195, and moves the post 182 along radial
region 195 into second axial region 196 where the outer tube 162 is
secured against rotation and the retainer 160 is maintained in the
extended position. Note that post 182 in its normal position is
seated within the first or second axial regions 194, 196 and needs
to be flexed proximally to release it and guide it through radial
region 195. Engagement within axial regions 194, 196 provides a
tactile feel to the user. The locking sheath 150 operates in the
manner described above and illustrated in FIGS. 13-15.
[0078] FIG. 20 illustrates an alternate embodiment wherein locking
sheath 130 is provided with two retainers 132, spaced apart as
shown. Locking sheath 130 is substantially identical to the locking
sheath of FIG. 6, in all other respects. Each retainer 132 is
attached to inner tube 136 at an edge and is identical to retainer
80 of FIG. 6. The retainers 132 are shown in their retracted
position, and are deployed simultaneously to their U-shaped
configurations upon rotation of the outer tube 134 as described
above with respect to the embodiment of FIGS. 6-10.
[0079] FIGS. 21 and 22 illustrate another alternate embodiment of
the locking sheath designated by reference numeral 200 (Only the
distal portion is shown). Locking sheath 200 has a retainer (flap)
202 extending from the outer tube 204 and a retainer (flap) 206
extending from the inner tube. Retainer 202 is attached, e.g.
welded, to retainer 206 so that upon rotation of outer tube 204,
retainer 202 and retainer 206 are moved to the deployed position.
The overlapping retainers 202, 206 increase the material strength
of the flap.
[0080] The tips or any regions of any of the foregoing introducer
sheaths can have radiopaque markers to provide visual indication of
the sheath tip location. The markers can take a variety of forms
such as a circular marker band wrapped around the outer tube or a
radiopaque material attached (e.g. welded) or otherwise applied
onto the tip or along other regions of the sheath. FIG. 18A shows a
marker band 198 formed in the distal tip, composed by way of
example, from black tungsten and placed during formation of the
tapered tip.
[0081] FIG. 18C shows an alternate embodiment of the radiopaque
marker insert, extending to the distalmost tip of the sheath 190'.
Ring shaped insert 198', preferably composed of black tungsten, is
placed at the distal end of the outer tube 190'. When heated, the
insert is blended into the outer tube 190'. The inner diameter D is
formed so that it is the same as the inner diameter of the inner
tube (not shown) to provide a smooth transition for the insertion
of instrumentation through the sheath. A small portion of outer
tube 190', designated by reference numeral 190a, typically does not
blend with the insert 198'.
[0082] The introducer sheath of the present invention can be made
of various dimensions. In a preferred embodiment, the sheath is
about 6 French or about 7 French in outer diameter and has a wall
thickness of about 0.014 inches (the inner and outer sheath each
having a wall thickness of about 0.007 inches).
[0083] The interior of the inner tubes of any of the foregoing
embodiments can have a hydrophilic coating to facilitate instrument
insertion through its lumen by reducing frictional contact. The
outer surface of the outer tube could also be provided with a
hydrophilic coating to reduce frictional contact with the skin and
vessel during insertion. To help keep thrombus from forming on the
device, an anti-thrombolytic coating can also be provided.
[0084] FIGS. 13-15 illustrate the introducer sheath of the present
invention in use. The introducer sheath 50 of FIGS. 6-10 is
illustrated and described (with the tubing removed for clarity), it
being understood however, that any of the aforedescribed introducer
sheaths would be utilized in a similar manner.
[0085] FIG. 13 illustrates introducer sheath 50 positioned inside a
vessel "v", such as a common femoral artery. Sheath 50 is inserted
through incision "i" in the vessel wall to gain access to the
interior of the vessel. Once positioned as shown, the outer tube 60
is rotated to deploy retainer 80 to an extended position as shown.
In this extended position, the sheath 50 cannot fit through the
incision "i". Consequently when surgical instruments such as a
balloon catheter shown in FIG. 15 are inserted and then withdrawn,
the retainer 80 will contact the vessel wall around the incision,
preventing undesirable withdrawal of the introducer sheath 50
through the incision. Being retained or "locked" inside the vessel,
various instruments can be inserted and withdrawn through the
sheath lumen 62 without the introducer sheath 50 becoming dislodged
and causing the problems associated with such dislodgement
discussed above. The pin and groove locking arrangement maintains
the retainer 80 in the extended (blocking) position as desired.
[0086] When the introducer sheath 50 is ready to be removed from
the vessel "v", the outer tube 60 is rotated in the reverse
direction, disengaging the pin and groove locking arrangement, to
thereby return the retainer to its retracted position substantially
flush with the outer surface of the outer tube 60. Thus, the
introducer sheath 50 can be withdrawn through incision "i".
[0087] When used in smaller vessels, not only will the retainer 80
prevent full withdrawal from the incision, but it will contact the
vessel wall "u" downstream of the incision as shown in FIG. 14.
This contact results in frictional engagement with the wall,
thereby restricting unwanted longitudinal movement of the
introducer sheath 50 during withdrawal of surgical instruments,
such as the balloon catheter of FIG. 15. The curved surface 81 of
flap 80 provides atraumatic contact with the vessel wall.
[0088] The introducer sheaths of the present invention can also be
utilized in other minimally invasive catheter procedures, including
non-vascular procedures such as genitourinary, biliary, and
gastrointestinal procedures which require instrument insertions and
withdrawals through introducer sheaths.
[0089] While the above description contains many specifics, those
specifics should not be construed as limitations on the scope of
the disclosure, but merely as exemplifications of preferred
embodiments thereof. For example, any of the sheath embodiments can
optionally be provided with holes for dialysis. Also, if blood flow
therethrough is not required, the retainers need not be provided
with an opening for blood flow. Although the introducer sheath is
preferably composed of Pebax material, other materials such as
urethane, nylon, polyethyelene, or polypropylene, or composites
with braided components, can be utilized. The sheaths could also be
slightly curved or bendable/shapeable. Those skilled in the art
will envision many other possible variations within the scope and
spirit of the disclosure as defined by the claims appended
hereto.
* * * * *